Variable-power optics have long been sought after for a wide variety of applications. One outstanding example of such applications is that of 3D image production. Relatively low cost, high quality and convenient 3D video, cinema and image displays have likewise long been sought after to capture viewer interest, enhance the viewing experience, increase the functionality of computer systems and/or create new uses for 3D imaging. To date, however, conventional 3D light imaging systems have fallen short of being low cost, high quality, convenient and/or suitable for video or cinema. Examples of conventional systems include stereographic systems that require specialized eyewear or headgear to provide one eye of a viewer with an image that is slightly different in perspective from the image provided to the other eye. Drawbacks of these systems include the necessity of wearing bulky, uncomfortable and/or inconvenient viewing devices.
Other types of conventional 3D light imaging systems include volumetric displays, such as voxel displays having many self-luminescent volumetric elements that are individually controlled to produce a 3D image and multi-planar displays having a plurality of variable-opacity screens spaced from one another onto which corresponding slices of each image are sequentially projected in rapid succession to create a 3D image. Drawbacks of these types of systems include the need for large, heavy and expensive display elements comprising either voxels or multiple planar screens.
Moreover, voxel and multi-planar displays by themselves do not project 3D images into free-space to make the images appear to “float” in space. Rather, the 3D images of these devices appear within the thicknesses of their display elements. That said, however, a real image projector may be used to project the 3D image of a multi-planar screen device or voxel device into free-space so that the 3D image appears to float in space beyond the projector. This arrangement is shown in connection with a multi-planar screen device in U.S. Pat. No. 6,100,862 to Sullivan and U.S. Pat. No. 6,466,185 to Sullivan et al., which are incorporated herein by reference. However, this type of system is large and heavy due to the multi-planar screen element and even more expensive than the multi-planar device itself due to the addition of the real image projector. What is needed is a relatively inexpensive and lightweight real imaging system.